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Due to the COVID-19 pandemic, IOI 2020 was hosted by Singapore online. Visit the official website to learn more.

Just finished   IOI 2020 was held online

IOI 1989

The 1st International Olympiad in Informatics was held in Pravetz, Bulgaria, from May 16-19, 1989. Six problems were presented to the jury of the event. The first problem (shown below as "Problem 1") was selected for the competition.

      Problem 1
      Problem 2
      Problem 3
      Problem 4
      Problem 5
      Problem 6

Note that the grading model changed at IOI'94 and beyond.
Before IOI 1994, a human evaluator would sit behind the competitor's computer and do the testing manually (enter test data through the keyboard, check the output on the screen). Starting from IOI 1994, an automatic grading process is used, with test input defined in files.

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A couple of volunteers maintain a separate page with stats about people who participated at the International Olympiad in Informatics.


The IOI publishes a journal every year, with original high-quality scientific papers related to education, contests and algorithms.